So, these are my trusty amp heads. I thought I may as well deal with these two together, since the differences between them are minimal, really.
I've been through a whole heap of different amps in my time as a bass player - Hartke, Trace Elliot, Gallien Krueger, SWR, Phil Jones - and I've loved every one of them. But it was the weight of these things that always bugged me, of course. It's every bass player's bugbear - lugging a heavy amp, along with a bass and big cab, to every gig is, frankly, a pain. Ok, ok, it could be worse, I could be a drummer. But still.
Anyway, when I read about the Genz Benz Shuttle around 2006, I I just thought, 'I have to try one of those': 600 watts, 3lbs, and small enough to fit in the pocket of my gigbag! With specs like that, it was of course just a bonus that the thing also sounds superb: I know these things are so subjective, but to my ears, the Shuttle is about the most transparent amp head I've ever played. By which I mean, it adds to or subtracts nothing from the sound of my bass - it simply gIves me an amplified version of the acoustic sound and feel of my bass. I use the basses I use because I like how they sound and feel - so the last thing I want is for the amp to change that before it gets to the audience's ears! Most amps I've tried change something subtly, and I find myself messing with the eq in an effort to restore whatever has been lost or added. Not on the Shuttle. I run the eqs flat on both of them.
I bought the 6.0 in about 2007, then the 9.2 in around 2010. Just as I bought my second Kingbass because I loved my first so much that I was terrified of being without it if it ever needed to be repaired for any reason, I bought the 9.2 because the 6.0 was just so perfect. Never had an issue with either of them, though, save for cleaning the fans every so often. And they are so small and light that I can easily take both of them with me to a gig, just in case.
There's one tiny difference between the two: the 9.2 feels like it has a slightly warmer and rounder bottom end, which is probably down to the fact that it has an additional 300 watts on top of the 6.0's 600 to push out those lower frequencies.
I love the simplicity of these things: the eqs are simply low cut/boost, high cut/boost and a sweepable mid. But as I said, unless the room requires some special eq treatment, I basically run them flat. There are three pre-shape buttons. I've never used them! And there's a tube preamp in them, so you can get a bit of grit out of them when necessary.
I also love the responsiveness. Some amps feel a little sluggish to me, and others feel like they 'even out' my playing, squashing the crescendoes and missing the nuances - again, it's a subjective thing, but the Shuttles feel like they react immediately and respect the dynamics of my playing.
And owning a Shuttle takes the pot luck out of touring. You can make polite requests in your rider for a specific type or brand of amp when you travel overseas to perform, but sometimes these things get lost in translation, or there's a problem with availability of certain amps in the country you're visiting. Many's the time I've requested a nice hi-fi full range bass amp, only to be presented with some sluggish woolly-sounding thing which really doesn't suit what I do at all. Now, since I can bring my amp in the pocket of my gig bag when I fly, that's one less unknown quantity to deal with!
Now the bad news: Genz Benz is no more - the company was bought out by Fender a few years ago, and the Shuttles were discontinued. However, the company's founder, Jeff Genzler, re-emerged recently at the head of his new Genzler brand. So, when my Shuttles finally bite the dust (not anytime soon, I'm sure), I know where I'll be looking first for my next amp.
Anyway, here's a pic of the two of them together, and please don't hesitate to drop me a line or comment if you have any questions.
And you can see and hear the 9.2 in action in my latest YouTube collaboration with Alberto Rigoni, here: https://youtu.be/Nn6GtZTm_18